Please do not copy any of the following information, text or pictures without obtaining permission first, and providing me with a text credit and a link to my website. I have spent many years researching and breeding charcoal bengals so please give credit where credit is due. If you see any of this information (*please see note below) anywhere else and you don't see my name on it, then the information was stolen.
*All the information on this page is copyright of Terra Sinclair, Pocket Leopards Bengals, except the ALC agouti theory, which is copyright of Joshua Dabbs.
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The Charcoal Bengal Group
If you would like to ask questions regarding the info. on this page or have anything to contribute, please post your questions to my new Charcoal group on Facebook. It is called "The Charcoal Bengal Group". I had previously created a charcoal bengals group on facebook, but I no longer have access to that group and will no longer be participating in that group. So if you want to discuss any of this with me, please join and participate in the new group "The Charcoal Bengal Group". I get several emails every day from people with questions about charcoals and about non-agouti/melanistics. It has become too time consuming answering every email individually. So please post your questions to the group so everyone can benefit from the information at the same time.
I am by no means saying that I know everything about this subject but I have studied, and bred for this specific color for quite a number of years. I continue to conduct test breedings and make note of the results.
I welcome any comments from anyone who has sufficient knowledge about the subject to add anything that might help us better understand this color (I will of course credit you with a text credit if I add your info to this page). What I put on this page, are mainly my own observations and theories on the subject, so my thinking may change from time to time, especially if more breeders become involved with breeding charcoals and more information becomes available. (update 9/9/11: Please note that this page is more of a "journal" type of writing, where over the years I have continually written down my findings and conclusions. Most of my earlier work is not dated but the last few years I have started to add dates to my entries. As you read down the page, you will see how thoughts have changed as facts are added to the page. Please don't take any conclusions or theories on this page as fact. Read all the findings for yourself and make your own conclusions. Thanks again for following me as I go through this journey!
Even though charcoal brown is an accepted color because it falls under the brown category, my goal is to eventually get the standard changed to include all of the brown colors as desirable instead of just a high degree of roufesing. One of the main reasons why is because I know that this color contributes greatly to my breeding program and can contribute greatly to other programs (more about that later) I also know that many charcoals are early generation cats, so being that it occurs naturally, it should be included in the standard.
(update 3/25/08 I believe the standard has been changed and it no longer states that a high degree of roufesing is preferred! This is wonderful news for our charcoal and cool colored bengals!)
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From my observations and test breedings I have found that the charcoal coloration can be inherited along with any other color bengal. To date, there are charcoal browns, charcoal silvers, and charcoal snows.
The fact that charcoal coloration can be inherited along with other colors besides just being an unroufesd brown has me convinced it is an entirely seperate gene or set of genes than just an unroufesed brown/black.
I would love to try and test breed to get some charcoal blues, etc. to see if the charcoal coloration can be inherited along with these other colors as well.
(update 1/1/10 - There is a blue that I think has a strong possibility of being a charcoal. He has a cape and is a darker blue color. He was genetic tested and is Aa so the possibility that he is a charcoal is strong. He will be bred and results will be published later)
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Please be aware that at this time, "charcoal" is not really a separate color designation, rather it is a description. Although through breeding, I am convinced that it is a separate gene that the brown/black gene and should be in it's own color class.
At this time however, most breeders use it to describe a brown cat that is at the very end of the color spectrum. It is on the opposite side of the spectrum of very red or orange cats that are highly roufesd. Instead, the charcoal brown has very little to no roufesing. *
In the middle of the spectrum would be other colors of brown like mahogany, golden, tawny, etc. (see color chart below)
(*update10/18/10: Please note that in the last few years there has slowly been a shift in the thinking of many breeders. Many breeders now think that the charcoal is a color that is inherited indecently of brown, thus referring to some silvers and snows as 'charcoal snows' and 'charcoal silvers'. This shift in thinking has been one of my goals for many years and it thrills me to finally see it taking place.)
note: this color chart is not meant to show all of the brown bengal colors, rather it is just used to show how charcoal brown and a roufesed brown are at the opposite ends of the color spectrum).
CHARCOAL BROWN
Charcoal browns, at maturity, will have jet black markings against a silvery grey background. Sometimes it takes awhile for the background color to come in but they are all born with the jet back markings (more on that later).
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| charcoal brown bengal (front) roufesd brown (back) |
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Charcoal and the ALC
It has been reported that there is a subspecies of charcoal colored ALC's. I know there are also a great number of charcoal colored F1's that are born. This may give us a clue to what causes the charcoal color within the bengal breed. Is it another mutation that came from the ALC? Perhaps. There is still a lot that is unknown about ALC genetics. Wild genes work differently. For an example, with the bengal, melanistic (or solid) is recessive. With the geoffroys cat, melanistic (or solid) is dominant.
(if anyone can provide a picture of a charcoal colored ALC if would be greatly appreciated)
For more genetic info about charcoal, see the bottom of this page under the subheading "charcoal and the non-agouti link"
Update 9/14/11: It has been reported that there is a breeder that bred a melanistic queen to her ALC stud several times and both times the litters were 100% charcoal. This news still needs to be confirmed. However, if this is true, it's helps to add weight to my long standing belief that the ALC has a link to the charcoal coloration, and that melanism also has a link to the charcoal coloration.
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Back Stripe/Cape or "Zorro Markings"
I have noticed that most charcoal (spotted) bengals have a back stripe (or some breeders call it a "cape"). In my opinion, all true charcoal spotted bengals should have this back stripe at one point in their lives. Some bloodlines seem to produce wider back stripes than other lines though.
The stripe is a very thick, black line running all the way down the back from the shoulders to the base of the tail. I'm not sure why this occurs so often but it may be that somehow the charcoal color is inherited as a pattern (thus lending some weight to my belief on the non-agouti gene is in a large way responsible for charcoal color, since the agouti gene has to do with the way a pattern is seen. Please see the subheading at the bottom of this page) ,thus creating the back stripe as part of the pattern.
Or perhaps it is as simple as this: being that the area along the back is usually naturally darker in most bengal cats (even non-charcoal bengals), when combined with the dark charcoal gene/genes, it's makes this area even darker thus creating the back stripe.
Below are some pictures of different charcoal cats with the back stripe.
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| click on pic to enlarge charcoal bengal |
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| click pic to enlarge (charcoal bengal, rear of picture) |
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CHARCOAL MARBLES
To date, I have only seen a few marble pattern bengals that I consider true charcoals. Even though I have produced many unroufesed marble bengals here, I would consider none of them to be true charcoal marble, with the exeption of the charcoal snow marble that is shown on my "snows" page.
Below is another picture of a true charcoal marble kitten.
(photos of the kitten below provided by Misty of Kajari Bengals)
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| click for larger pic of charcoal marble bengal (photo courtesy of Kajari Bengals) |
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| charcoal silver marble kitten -clcik pic for larger |
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Two Different Kinds
I have also noticed through breeding charcoals that there has been two different types of charcoal browns born here (and in other catteries too now that more people are breeding for charcoals). Although this coloring affects silvers too, the following information is referring to charcoal brown cats.
The first is born with jet black markings and a almost white background color. For descriptive purposes, I'll call this type of charcoal "light charcoal"
From just looking at them they look very much like a dark marked silver. It is almost impossible to tell them apart from a silver. There are two ways to tell is the kitten is a silver or if it is a charcoal brown.
1.)If it is not a silver it will not have a white undercoat (fur right next to the skin).
2.)If neither of the parents are a silver, the kitten cannot be a silver.
Later on when the cat matures, it takes on that characteristic silvery grey background color.
Below are picture examples of "light charcoal" browns that look silver at birth or at a young age.
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| click on pic to enlarge pic of charcoal brown bengal kitten |
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| click pic to enlarge pic of charcoal brown bengal kitten |
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| click pis to enlarge pic of charcoal brown bengal kitten |
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The second type of brown charcoal is born very, very dark. The background color is as dark as or almost as dark as the markings. For descriptive purposes, I'll call this 'dark charcoal"
This type
of cat is not a melanistic because melanistics are entirely black, even on the feet, face and belly. In contrast, the dark charcoal, although predominately black, will still have light color on the face, feet and belly. (see picture examples below)
Sometimes the background will gradually lighten and take on that characteristic silvery grey background color, but sometimes it won't and the cat will stay predominately black at maturity. (see picture examples below)
To date, I know that both browns and silvers can either be a "light charcoal or a "dark charcoal" but the pictures below are all of charcoal browns.
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| dark charcoal brown bengal kitten |
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| click on pic to enlarge pic of dark charcoal brown bengal |
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| click on pic to enlarge picture of these brown charcoal bengals |
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Charcoal Glitter
Almost all the charcoals I have produced here have been glittered. As a matter of fact, many of them have been extremely glittered. The charcoal brown will not have the golden type of glitter, rather the color of the glitter looks like little strands a very thin sterling silver or mercury. I have noticed this glitter color looks different from the "crystalline" type of glitter found on some snows and silvers. Mostly, the glitter can be found on or in among the black fur and not so much on the background fur (unless it's there but less detectable against the lighter background color). I have been able to actually pluck out strands of glittered fur. The glitter seems to reach the entire length of the hair shaft, unlike "Mica" glitter, which only affects the very tip of the hair. It is also unlike "satin" glitter, because although satin glitter reaches down the entire hair shaft, satin glitter seems to have more of a glossy look rather then a silvery metallic look. Two different types of glitter genes have been identified in bengals (Satin and Mica). Weather or not this metallic glitter is the result of one of these genes, or perhaps both of these gene combined, or another glitter gene entirely, I do not know. I do know that it looks different than any of my other non-charcoal bengals who exhibit glitter (both satin and mica glitter).
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Charcoal Tarnish
Since charcoal brown are considered brown, no such thing as tarnish technically exists on the charcoal bengal. However, I have noticed that a number of brown charcoals do get a "tarnished" look on the face, feet, and ears. Many times it develops later, like how a silver bengal would develop tarnish.
A charcoal brown that has this warm color is not to be confused with a "cool brown" color of cat. A non-charcoal, "cool brown" will develop warm color (but not as warm as most other browns) in the background of the coat. A charcoal brown will usually not develop any roufesing in the background of the coat except in the "tarnish" areas described above.
A charcoal brown can also get a tarnished look on the black markings where, like the melanistic, too much sunlight can turn some the black part of the coat a brownish to dark purplish color. As soon as the cat is restricted from access to sunlight, the jet black color returns. Or sometimes as a result of nutritional deficiences the color can also fade. Certain times of the year the coat can fade out on individual cats as well.
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"Charcoal Brown" VS. "Cool Brown"
There is not as much known about charcoal brown as there is about other colors of brown at this time. Since this is the case, a great number of bengal breeders are mis-identifying cool brown colored cats as charcoal brown. Looking for the silvery grey background coat (at maturity) with no warm background color can help them to identify a charcoal apart from a cool brown with very little roufesing. I have experianced very cool brown cats and charcoal brown cats born in the same litter. Sometimes it takes an experianced eye to tell them apart, much like it takes an experianced eye to tell silvers and snows apart if both are born in the same litter, or to tell the different kinds of snows apart, if born in the same litter or compared side by side.
Below are some pictures of charcoal browns and non-charcoal, "cool brown" colors of cats and kittens. See if you can figure out which is which. Click on the picture to make it larger and for the answers.
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CHARCOAL SILVERS:
At this time, charcoal silver is just another variety of the regular silver color. On the registration papers a charcoal silver would be registered as just 'silver' (just as a charcoal brown would be registered as "brown" and not "charcoal or "charcoal brown" ). As brought out before, I am quite convinced that charcoal should have it's own color designation since it can be inherited along with any other bengal color.
Sometimes silvers are born that are very dark, almost black, just like how a "dark charcoal brown" is born( *see my info on this page about "dark charcoals" and "light charcoals"). Some people might mistake them as a silver smoke which is a melanistic that also carries the silver gene. " Charcoal silvers are not silver smoke though.
At first these kittens will have a dark body but you can clearly see the white markings on the face, that's how you can tell the difference between them and a silver smoke. A silver smoke will have the "smokescreen" over the entire body, even the face.
Dark charcoal silvers go through an amazing transformation. The background color starts to lighten until a pattern is revealed. Charcoal silvers end up with a jet black pattern and a silver to white background coat. The hair near the skin will still be pure white.
Take a look at the pictures below to see how a charcoal silver kitten transforms in color. It is interesting to note that most charcoal browns transform colors in much the same way, most are also born with very dark fur over much of the body except the face (for more info on that see the 'dark charcoal" info on this page").
Below are some pictures of charcoal silvers and how they transform in color.
Please note that not all charcoal silvers develop like this. Some have the adult coloring from birth. An example would be my stud boy "Arty". He never had a smokescreen type of coat.
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| 3 days old (click pic for larger) |
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| same kitten at 15 days old |
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| same kitten (Cozy Counrty Kairu) as an adult |
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CHARCOAL SNOWS
Here at Pocket Leopards we are producing snows that are charcoal in color. They have the same characteristic as charcoal browns and the charcoal silvers. The only difference is that they are snow.
We have produced charcoal snows in both seal lynx point and seal mink. The seal lynx points so far have been born white like a normal seal lynx point, but once they mature they mature with a dark pattern like any other charcoal would.
Zorro markings tend to show first and body pattern darkens slowly. With the seal lynx points the face mask is generally the first to show out of any other body markings and gets darker quicker.
Pictures below of a charcoal snows born here. Notice in some of the pictures how charcaol snows develop. Getting darker patterns as they grow.
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| "Sage" charcoal mink bengal approx. 4 months old |
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| "Sage" charcoal bengal mink approx. 4 months old |
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| Pocket Leopards "Sage" (charcoal silver mink bengal) at 5 months (Sage now belongs to Legacie bengals) |
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| Pocket Leopards "Sage" (charcoal silver mink bengal) at 5 months (Sage now lives at Legacie Bengals) |
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| Pocket Leopards "Blondie" (charcoal SLP bengal) a few weeks old |
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| Pocket Leopards "Blondie" - charcoal SLP bengal - born 3/29/09 |
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| Pocket leopards "Blondie" 13 weeks old (charcoal SLP bengal) pattern darkening. More pics will be posted as she grows. |
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| Pocket Leopards 'Dreams', charcoal SLP marble at approx 1 week old |
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| Pocket leopards "Dreams" charcoal SLP bengal at approx. 10 wks old |
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| Pocket Leopards "Dreams" charcoal SLP at approx. 1 year old. (Picture taken by Jenna of Naamah Bengals) |
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| Pocket Leopards "Metallica" (charcoal mink) a few days old. |
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| pocket leopards Metallica 13 wks old (charcoal mink bengal) |
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| Charcoal SLP marble (white at birth) along with her melanistic littermate. |
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| same charcoal SLP at a couple weeks old |
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| 10/18/10 Pocket Leopards "Malibu" charcoal seal lynx point bengal at 4 months old |
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| Pocket Leopards "Zorro" charcoal seal lynx point bengal at 4 months old. 10/18/10 |
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| Pocket Leopards bengal kitten (unamed) charcoal seal mink bengal at 4 months old. Pic taken on 10/16/10 |
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| Pocket Leopards kittens , charcoal seal lynx point bengal and charcoal seal mink bengal |
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The following information is what I wrote up about what I suspect, what seems to be fact, and what I don't know because test breedings have not been done to my knowledge. If you have done some test breedings and can add anything to this, please contact me. I would love to work together with other breeders to further my knowledge on this color by more test breeding. The more people doing the test breedings, the faster we can answer some of these questions to a certainty.
POSSIBILITIES FOR MODE OF INHERITANCE
1.)Polygenic trait
(therefore the Mendel mode of inheritance would not apply and there are no dominant genes, the genes work in a totally different way than simple recessive/dominant.)
2.)Inherited as a pattern instead of merely a color. Like the whited tummy, the charcoal could be inherited as a pattern, and this would explain why charcoals have the "back stripe" (or cape). I also know that the agouti locus plays a large role in the charcoal color. All charcoals tested thus far have been Aa. So it is possible that charcoal could have something to do with pattern.
3.)It is possible that the marble pattern can act as some sort of modifier gene, thus eliminating the back stripe.
4.) A modifier or extension or mutation of the non-agouti gene.
I also decided to write down what seems to be fact, and what I don't know. If any of you have anything to add, or can counter any of this, please do so!
WHAT SEEMS TO BE FACT
1.)Non-charcoal can be carriers of charcoal
2.)It only takes one charcoal (or charcoal carrier) parent to produce charcoal offspring
3.)One charcoal parent (or carrier) will not produce all charcoal kittens, in every litter, 100% of the time, when bred to a non-charcoal (or non-carrier).
4.)Neither parent actually has to be a charcoal (in phenotype) in order to produce charcoal offspring.
WHAT I'D LIKE TO GENETICALLY TEST FOR:
1.)To test to see if all charcoal colored cats carry for the non-agouti gene (melanistic) (Aa). So far evidence shows that they all do. However I need more data to prove or discount this theory.
(if anyone reading this has a charcoal cat and know for sure if it is/or is not genetically Aa, or would be willing to submit to a genetic
test, please let me know.) * please see updated info below under the "charcoal and non-agouti link" subheading
I already know that non-charcoal cats that "carry" for charcoal do not have to be Aa.
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The non-agouti link to charcoal
So far, all charcoals that I have studied carry for one non-agouti gene (Aa) * I have a new thought on this, after you read this information, please see the article on this page dated 9/8/11 "One giant step forward or two steps back".
All cats who inherit two copies of non-agouti are said to be melanistic (aa) Two copies on the non-agouti gene changes the way the pattern can be seen. The background color is the same as the pattern color and the cat is said to be "self colored". There is still a pattern, but it is hidden by the background color.
However, in charcoals, they only have one non-agouti gene (Aa). Not all cats who are Aa are charcoal, but all charcoals are Aa.
What causes some cats who are Aa to have a charcoal phenotype, but others who are Aa to not have a charcoal phenotype? There are other (still unknown) genes involved, or perhaps another mutation to the Agouti locus.
I also have observed that in all of my breedings that produced charcoal, if there are no charcoal parents involved, then one parent must have one copy of non-agouti in order to get charcoal offspring out of the mating.
A non-charcoal parent can carry for charcoal and not carry non-agouti gene (can be AA at the agouti site). The other parent must carry a non-agouti gene (either be Aa or aa) in order for charcoals to be produced from this pairing.
Since charcoal is not simply the non-agouti gene working by itself, not even all melanistic (cats with two copies on non-agouti) can produce charcoals. They can produce them with a charcoal 'carrier', but may not produce them without a 'carrier" to breed them to.
There defiantly seems to be a strong link between non-agouti and charcoal. However, non-agouti is not the end all to this color. There are plenty of cats who carry for non-agouti and they never produce a charcoal. So just merely inheriting a copy of non-agouti will not work in producing charcoal. Not all cats who carry one non-agouti gene are charcoal themselves either, but ALL charcoals (tested this far either through breeding or genetic testing) are carriers of one non-agouti gene.
How can a cat with only one copy of non-agouti express a form of melanism? That question remains. It could be that the ALC has introduced a new mutation of the agouti locus into the mix. What turns these genes on and off? Why aren't all cats who are Aa phenotypically charcoal? Again, these are questions that remain unanswered for a certainty. But here is some food for thought. I found the following information on Wikipedia about the Agouti locus:
There is also a theoretical "black modifier" gene, Bm, which in its recessive form, bmbm, causes tabby cats to turn into the colors amber or light amber. This gene could be more appropriately called "agouti modifier" and is probably related to the extension locus (the melanocortin receptor) or its ligands, melanocyte stimulating hormone and agouti signaling protein. This phenomenon was first identified in Norwegian Forest Cats. Other forms of extension mutations have been seen in many breeds (and domestic cats), resulting in unique forms of tabby expression.
I am not suggesting that charcoal is due to the "black modifier" gene itself, but what I am suggesting is that charcoal is some form of modified agouti gene. Very possibly an extension mutation or a mutation of the Agouti gene itself.
More test breedings and genetic testing needs to be done to further see how these genes work. If you are willing to have your charcoal tested to see if they carry non-agouti gene, please contact me.
(note: Only non agouti can be DNA tested for at this time. Since it is still not known what gene or genes are responsible for charcoal, we cannot yet test for charcoal.)
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6/27/09
Charcoal Gene Identified?
ALC agouti gene theory
(Although I think this theory is not entirely correct, I am leaving it here for learning purposes. Please see my article after this entitled "Old Thoughts Anew")
Joshua Dabbs has taken the info and data from my web page, and after much discussion with me, has pieced it together to form a viable theory on charcoal "genes".
(please remember this is just a theory, so don't take anything here as fact)
Here is what he suggests:
Extensive research in both breeding the charcoal and through testing and encouraging others to test we have been able to identify the link between the non-agouti gene and the appearance of the charcoal (as all charcoals tested at the agouti locus have returned as Aa). There have been multiple theories Terra has created, with focus on a mutation at the agouti locus or the extension gene locus. But the more she and I have discussed it the more we see that perhaps it's much simpler than that...
Since the bengal breed originates from the hybridization of a separate species, I believe the real culprit to be the ALC. It's been scientifically proven that the non-agouti gene is an independent mutation within a species gene pool. Since the ALC does not have a non-agouti mutation, it's a safe bet to say that the ALC's agouti gene may not be completely dominant over the domestic non-agouti gene. To simplify, I believe the charcoal coloration to be the result of incomplete dominance of the ALC's agouti gene being paired to the domestic non-agouti gene. Since the charcoal coloration most commonly occurs in the filial (early generation) generations, this further verifies this theory. Over the years though, through selectively breeding the ALC's agouti gene was largely replaced with the domestic variant, or the non-agouti gene bred out of the lines ( perhaps because the standard demanded for highly roufesed cats, charcoal colors were not selected for, thus reducing the instances of ALC agouti in the breed *) . Every so often, like in Terra's case, a charcoal carrier (one who carries for the ALC agouti gene, but not the non-agouti) is produced that when paired to a non-agouti carrier... the end result is the charcoal. "
(bold text above is copyright of Joshua Dabbs and not to be copied without his written consent)
* This is just a simplified explanation of this theory. Here is a another way to look at it. Imagine that the charcoal "gene" is the alc agouti and it is represented by Aš. Regular domestic agouti would be A. All charcoals would be Aša. Now you can take this and apply it to a punnett square and see what you would get out of each breeding (statistically).
All the test breedings done, according to this formula, now make sense. It makes sense that a non charcoal can be a carrier of the "charcoal gene" (the charcoal gene is Aš). For instance, My stud Native son is not charcoal and does not carry for non-agouti, yet when paired with a non-agouti he makes charcoals. So it can be said that Native Son is an (Aš A) (one charcoal gene and one non-charcoal, regular agouti gene). When I pair him to Wildstyle, who is not a charcoal, but carries for non-agouti (Aa) I get some charcoals. The reason why is because Native son passes on the Aš and Wildstyle passes on the a.
If this is a correct. That means that by pairing charcoal (Aša) X charcoal (Aša), we should be able to get charcoals (Aša), melanistics (aa), and non-charcoals (AšAš) . We can then take these cats, that are "pure" for the ALC agouti gene (AšAš) and breed them to a melanistic and we should get 100% charcoal kittens.
TICA's geneticist has already been contacted. After explaining our theories, she has agreed , and is looking into seeing what it'll take to compare agouti sequences. So we may have ourselves genetic proof to boot.
* added note by Terra
(according the the above theory, if a cat carries for charcoal, but is obviously not charcoal, it can't also carry for melanistic because that would automatically make the cat charcoal. So if you have a non-charcoal who has produced BOTH charcoal AND melanistic/smoke with another non-charcoal, we want to know about it! We will need photographs of both parents and the kittens and if possible, DNA testing)
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| According to our theory, the above represents what you would get from a charcoal to charcoal breeding |
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| The above image represents what you would get from a non-charcoal carrying for charcoal bred to a non-charcoal carrying for melanistic/non-agouti |
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10/07/10
OLD THOUGHTS ANEW
Since the writing of the preceding article, there has been some evidence that the theory above may not be entirely on spot.
In my studying breedings, there is evidence to suggest that with one charcoal parent, that the one charcoal may be "self sufficient". What I mean by that is one charcoal parent may be able produce charcoal offspring without the genetic help of the other parent. If this is the case, the charcoal gene would need to be some sort gene that can be (but not always) passed along with one copy of non-agouti. If this is the case, this would also mean the theory above( that the charcoal gene is actually a ALC Agouti gene) can not be entirely correct.
Don't misunderstand me as I am not saying that the charcoal gene could not have come from the ALC, because it could have, but I am only saying that it seems at this point that it may not be inherited the way the ALC agouti theory suggests.
In order to test to see if this is the case, what I will need to do is the following:
Breed a charcoal to a mate that is AA (or completely dominant at the agouti site) and not known to carry for charcoal.
If any charcoal offspring are produced, then I can conclude that either the AA parent carries for charcoal OR the one charcoal parent is sufficient to pass on both the charcoal gene and non-agouti at the same time.
So to test to see if one charcoal parent is "self sufficient", I would need to take the non charcoal mate above and breed the non charcoal mate to a cat known to be Aa but not charcoal ( a non charcoal with one copy of agouti, and one copy non-agouti). If no charcoal are ever produced from pairings between these two I can reasonably conclude that a charcoal is "self sufficient". Of course we should do many more than one test breeding to confirm this.
In short, what I am suggesting is that charcoal can be inherited both of these ways (but not both ways at the same time):
1.) Inherited entirely from one charcoal parent. The one charcoal parents passes on the charcoal gene (whatever that may be) and one copy of non-agouti.
2.) One non charcoal parent passes on a copy of a charcoal gene, and the other non charcoal parent passes on a copy of non-agouti.
Of course as always, my findings will be posted on this page when I have enough evidence to think that there is something significant to post.
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ONE GIANT STEP FORWARD OR TWO STEPS BACK?
originally posted on 9/8/2011
Today I found out that the kitten below was DNA tested as AA and not Aa as all other charcoals with the charcoal phenotype have been confirmed to be, either through genetic testing or through breeding.
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| Possibly a charcoal brown that is AA or completely dominant at the Agouti site. Picture courtesy of Gail at Kiabindhi Bengals. |
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Perhaps the cat above just needs to be retested, and arrangements are being made to have him retested. Or perhaps he is just a brown (not charcoal) with a wide spine band. Mara from Dazzledots bengals said the following: "Maybe he is just a BST with a spine band. That would account for the "cape". Gogees Heavenly Daze has an extremely wide spine band and passed it down to his son "Gogees Spotlight On Me. We got only one or two spine bands down from Frosted, but it is in his genetics".
However, if this cat, who has the phenotype of a charcoal (not going solely off of the spine band or cape, but also in the color description from the owner who says the cape is jet black and the color on his face in real life is a very pale cool brown) , turns out to be completely dominant at the agouti site, and he turns out to be charcoal (though there's no way to confirm that at this time) here is my theory of what may be happening. (Again, please don't take my conclusions as fact)
Charcoal seems to be a "switch" of sorts, where the charcoal gene (or genes) turn down or reduce the effectiveness of the dominance of the one Agouti gene that Charcoals carry. In the case of this boy who was tested AA, perhaps a cat can be AA (or full Agouti) and still be charcoal if the charcoal gene is so strong as to override even two copies of the Agouti. You just never really see the charcoal phenotype with two copies of Agouti because normally the charcoal gene or genes are not strong enough to make enough of an impact on the coat color to notice that these full Agouti cats are genetically charcoal as well.
Perhaps non-charcoal "carriers" of Charcoal (like my boy Luxor was, and my boy Native Son was) are actually charcoals themselves genetically but not in phenotype. No one can tell that they are charcoal because they do not have strong enough charcoal genes to override the pair of Agouti genes working double time.
In this case, you can kind of compare the charcoal gene or genes to the Inhibitor gene. The Inhibitor gene inhibits (or prevents) the background color from showing. Sometimes the inhibitor gene is not strong enough to completely inhibit color and some of the background color shows through (that's how you get tarnish). It is said that a cat that is completely dominant at the Inhibitor site is usually less tarnished than one that only carries one copy of Inhibitor. But, there are exceptions. Sometimes even cats who at completely dominant at the inhibitor site, still have some tarnish. Some worse than others. It would depend on how strong those Inhibitor genes are working.
Further, perhaps charcoal has it's own gene site, like the Inhibitor gene does, and you can have two copies of the charcoal gene or only one copy of it. If this is the case, the two copies might be enough to do battle with the two dominant Agouti genes and you would be able to see the charcoal phenotype. Because only recently the charcoal is being selectively bred for by many more breeders, we will see more of these types of charcoals that are AA at the Agouti site, which are also completely dominant at the Charcoal site (still a theoretical gene site). This gene site could also be similar to how the dilute gene (blue) works, where a completely different gene site will affect the brown/black gene site. Instead, the charcoal gene site could be an entirely different gene site that affects the Agouti gene site, and instead of diluting the color like blue does to the "B" site, charcoal intensifies dark color.
Or, perhaps there is a mutation at the Agouti site itself, like there is at the color point gene site where you have different color point genes on the same site. Maybe there are different Agouti genes at the Agouti site. For instance the regular Agouti could be represented as A and the mutation could be represented as A2, The combination of possibilities could be numerous. They could be AA, Aa, aa, AA2, A2a, A2A2. Any one of these with the 2 would be a charcoal. This could account for the difference in intensity of the charcoal color. Some being almost totally black and some being much lighter depending on how the A2 is inherited. (Please note that I have a very limited knowledge of how genetics work, so if this genetic combination is not possible, please enlighten me)
So if this is the case and if all charcoal are NOT in fact Aa at the agouti gene site, does that mean that we have taken two steps back in figuring out what charcoal is and how to test for it. I would say no. I would say it is the opposite and it is one giant step forward. Every piece of the puzzle gets us closer to the overall picture, weather or not it proves the previous thinking to be inaccurate.
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